物体超重和失重现象 ,是物理教学中的一个难点 .仅从理论上分析物体的超重和失重现象 ,学生感到很抽象 ,不好理解 .要通过实验让学生能观察到这一现象 ,是有一定的难度 ,因为物体在加速或减速运动 ,是处于动态过程 ,而且时间很短 .若是用弹簧吊着重物做加速上升或加速下降时 , The phenomenon of overweight and weightlessness of objects is a difficult point in physics teaching. It is only theoretically analyzed that objects are overweight and weightless. Students feel very abstract and not well understood. Students must be able to observe this phenomenon through experiments. The difficulty, because the object in the acceleration or deceleration movement, is in a dynamic process, and the time is very short. If you use a spring to lift heavy objects to accelerate or accelerate the decline,